Internet DRAFT - draft-trossen-rtgwg-rosa-arch
draft-trossen-rtgwg-rosa-arch
Network Working Group D. Trossen
Internet-Draft Huawei Technologies
Intended status: Standards Track LM. Contreras
Expires: 10 January 2024 Telefonica
J. Finkhaeuser
Interpeer gUG
P. Mendes
Airbus
9 July 2023
Architecture for Routing on Service Addresses
draft-trossen-rtgwg-rosa-arch-01
Abstract
The term 'service-based routing' (SBR) captures the set of mechanisms
for the steering of traffic in an application-level service scenario.
As in the related use case and gap analysis drafts, we position this
steering as an anycast problem, requiring the selection of one of the
possibly many choices for service execution at the very start of a
service transaction.
This document outlines a possible architecture for realizing SBR so
as to address the issues identified in the use case and gap analysis
companion documents, specifically aiming at the realization of the
requirements in the latter document. We outline the architecture,
with pointers to possible realizations of the interactions, while
also outlining possible extensions to a base SBR capability through a
ROSA system as an outlook to possible richer capabilities.
Status of This Memo
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This Internet-Draft will expire on 10 January 2024.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Summary of ROSA Design . . . . . . . . . . . . . . . . . 3
1.2. Overview of Draft . . . . . . . . . . . . . . . . . . . . 5
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6
3. ROSA Design . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1. System Overview . . . . . . . . . . . . . . . . . . . . . 7
3.2. Examples of Possible Message Types . . . . . . . . . . . 10
3.3. Changes to Clients to Support ROSA . . . . . . . . . . . 12
3.4. SAR Forwarding Engine . . . . . . . . . . . . . . . . . . 13
3.5. Traffic Steering . . . . . . . . . . . . . . . . . . . . 17
3.5.1. Ingress Request Scheduling . . . . . . . . . . . . . 18
3.5.2. Routing Across Multiple SARs . . . . . . . . . . . . 19
3.6. Interconnection . . . . . . . . . . . . . . . . . . . . . 21
4. Extensions to Base ROSA Capabilities . . . . . . . . . . . . 22
4.1. Supporting Different Namespace Encodings . . . . . . . . 22
4.2. Supporting Multi-Homing of Service Instances . . . . . . 23
4.3. Supporting 0-RTT TLS . . . . . . . . . . . . . . . . . . 23
4.4. Supporting Transaction Mobility . . . . . . . . . . . . . 24
4.5. Supporting Service Function Chaining . . . . . . . . . . 24
4.6. Supporting Privacy-Compliant Communication . . . . . . . 24
5. Prototype-based Insights . . . . . . . . . . . . . . . . . . 25
6. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . 25
7. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 25
8. Security Considerations . . . . . . . . . . . . . . . . . . . 26
9. Privacy Considerations . . . . . . . . . . . . . . . . . . . 27
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 27
12. Informative References . . . . . . . . . . . . . . . . . . . 27
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31
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1. Introduction
As noted already in [I-D.mendes-rtgwg-rosa-use-cases], we can
recognize a growing proliferation of serverless service provisioning
methods that allow for dynamically deploying service endpoints, not
just in centralized data centres but distributed across network
locations and end devices, including those provided by end users
directly.
As identified in [I-D.mendes-rtgwg-rosa-use-cases], the key problem
in providing services in a distributed setting is that of mapping an
application level identifier, e.g., a domain name, to a routing
locator under which the device hosting a service could be reached.
We refer to this as 'service-based routing' (SBR). As further
identified in [I-D.mendes-rtgwg-rosa-use-cases], a key problem to SBR
is the possible latency that may incur for such mapping operation,
while also enabling dynamic updates to the mapping result, possibly
constrained by service-specific policies.
Overall, we characterize SBR in an environment that makes use of,
possibly virtualized and distributed service endpoints in several
network locations, as needing to make any anycast decision, selecting
one out of possibly many choices for the service endpoint, where such
choice may change frequently.
In the remainder of this document, we present an architecture for
such anycast decision method, addressing the key issues outlined in
[I-D.mendes-rtgwg-rosa-use-cases] in an approach we term 'routing on
service addresses', or ROSA in short. In summary to the issues
identified in [I-D.mendes-rtgwg-rosa-use-cases], the main design
goals for ROSA can be identified as (i) supporting the need for
'dynamicity' for the anycast decision, (ii) providing the required
'efficiency' of the anycast decision to improve on existing explicit
resolution methods (and their incurring latency through the required
resolution step) as well as (iii) enable the 'service specificity' of
the anycast decision.
1.1. Summary of ROSA Design
The key approach to Routing on Service Addresses (ROSA) is to replace
the usual DNS+IP sequence, i.e., the off-path discovery of service
name to IP locator mapping, through an in-band discovery to a
suitable service instance location for a selected set of services,
not all Internet-based services, followed by the usual direct client-
service transfer using existing IP-based data path solutions.
With this in mind, the basic functionality of ROSA can be described
as follows:
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1. A client sends an initial packet, 'directed' to service address
S, to a special shim (ROSA) overlay.
2. The shim overlay routes the packet based on the service address
to one of the possibly many service instances for S over an
existing IP network. For this, mappings between S and the known
service instance locators are used by the ROSA overlay, replacing
the role of DNS records, while the selection of the 'suitable'
service instance locator may use service-specific policies (and
parameters).
3. The chosen service instance delivers its network locator SI in
the response to the initial packet back to the client.
4. The client will now continue to use SI in native IPv6 packets to
direct any subsequent packets to the chosen service instance.
This is to support possible ephemeral state created at service
instance as a consequence of previous exchanges.
Steps 1 through 4 are repeated for every new service transaction,
allowing those transactions now to be served at any of the available
service instances albeit keeping one transaction at one chosen
service instance! Steps 1 through 4 may also be repeated in case of
mobility. For stateless services, only steps 1, 2, and 3 are
executed.
In order to react to system, e.g., network but more importantly
service changes, ROSA achieves dynamicity, as mentioned in the
previous section, by employing a routing-based approach able to map
service addresses to routing locators, where mappings of service
addresses to routing locators are pushed to the (shim overlay)
elements, enabling to perform the translation from a service
addressed packet to an IP-addressed packet on the data path. When
using, e.g., eBPF-based techniques in SW-based routers, such approach
can achieve 100s of thousands of resolution steps per ingress node,
as discussed in Section 5.
The above functionality may be realized at various layers, which a
wider architectural discussion on ROSA will need to investigate
further. For instance, one could apply the above capability through
an application layer protocol, such as HTTP, akin to what ALTO
proposes (or as an extension to ALTO solutions). Alternatively,
methods developed by the MASQUE WG could be used (and suitably
extended) to employ a transport level realization of the in-band
functionality.
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While we do not intend to pre-empt any conclusion of this
architectural debate, we intend to outline an example design in this
document that provides what we see as the lowest possible layer
realization. Specifically, we outline the realization at L3.5,
employing an IPv6 extension header based approach. This approach
preserves a key assumption for a realization of the above
functionality, namely to be realized as an overlay, thus not being
linked into necessary ISP-level deployments, but operate akin to
choosing your DNS server at the client, thus fostering the possible
privacy of communication between clients and a set of services.
Furthermore, we believe that this chosen level of realization allows
for the broadest support for transport and application protocols
alike since the initial IP packet, realizing the in-band resolution
step, can include upper layer, i.e., transport and/or application-
level, data within the normal payload of the IP packet, achieving the
desired removal of the explicit resolution step as we use today
through the additional EH content.
Additionally, similar to application-level solutions, the positioning
as a (L3.5) shim overlay facilitates the exposure of service-specific
selection policies from the service to a ROSA provider through
explicit commercial relations, separate from those defining the
routing policies in the underlay network.
Unlike deploying name-based routing solutions at the underlay,
scalability here is achieved by limiting the resolution to those
services explicitly announced to the service routing (i.e., ROSA)
overlay. Thus, ROSA does not aim to replace ALL service routing
through the above proposed steps, but focus on those services
explicitly announcing their desire for a ROSA-based resolution to an
appropriate ROSA provider. The assumed explicit (often commercial)
relationship between the service provider and the ROSA provider is
what allows for controlling the scalability requirements of the
elements realizing the ROSA overlay.
1.2. Overview of Draft
In the remainder of this document, we first introduce in Section 2 a
terminology that provides the common language used for the wider ROSA
work. We then outline the design in Section 3 with possible
extensions to this basic design discussed in Section 4, leaving space
for insights from an early implementation of such design in
Section 5.
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2. Terminology
The following terminology is used throughout the remainder of this
document:
Service: A monolithic functionality that is provided according to
the specification for said service.
Composite Service: A composite service can be built by orchestrating
a combination of monolithic (or other composite) services. From a
client perspective, a monolithic or composite nature cannot be
determined, since both will be identified in the same manner for
the client to access.
Service Instance: A running environment (e.g., a node, a virtual
instance) that provides the expected service. One service can
involve several instances running within the same ROSA network at
different network locations.
Service Address: An identifier for a specific service.
Service Instance Address: A locator for a specific service instance.
Service Request: A request for a specific service, addressed to a
specific service address, which is directed to at least one of
possibly many service instances.
Affinity Request: A request to a specific service, following an
initial service request, requiring steering to the same service
instance chosen for the initial service request.
Service Transaction: A sequence of higher-layer requests for a
specific service, consisting of at least one service request,
addressed to the service address, and zero or more affinity
requests.
Service Affinity: Preservation of a relationship between a client
and one service instance, with the initial service request
creating said affinity and following affinity requests utilizing
said affinity.
ROSA Provider: Realizing the ROSA-based traffic steering
capabilities over at least one infrastructure provider by
deploying and operating the ROSA components within its defining
ROSA domain.
ROSA Domain: Domain of reachability for services supported by a
single ROSA provider.
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ROSA Endpoint: A node accessing or providing one or more services
through one or more ROSA providers.
ROSA Client: A ROSA endpoint accessing one or more services through
one or more ROSA providers, thus issuing services requests
directed to one of possible many service instances that have
previously announced the service address provided by the ROSA
client in the service request.
Service Address Router (SAR): A node supporting the operations for
steering service requests to one of possibly many service
instances, following the procedures outlined in Section 3.5.
Service Address Gateway (SAG): A node supporting the operations for
steering service requests to service addresses not announced to
SARs of the same ROSA domain to suitable endpoints in the Internet
or within other ROSA domains.
3. ROSA Design
This section outlines the design of a shim layer relying upon IPv6 to
provide routing on service addresses (ROSA). It first outlines the
system overview, before outlining the possible interfaces to the IP
layer (Section 3.2 and applications in ROSA endpoints (Section 3.3),
followed with the various operational methods of ROSA in terms of
forwarding operations (Section 3.4), traffic steering methods
(Section 3.5), and interconnection (Section 3.6).
3.1. System Overview
Figure 1 illustrates a ROSA domain, interconnected to other ROSA-
supporting domains via the public Internet through the Service
Address Gateway (SAG), where a ROSA domain may span one or more IPv6
underlay domain. Section 3.6 provides more detail on how to achieve
interconnection between ROSA domains.
ROSA is positioned as a shim overlay atop IPv6, using Extension
headers that carry the suitable information for routing and
forwarding the ROSA service requests, unlike [I-D.eip-arch] which
proposes to include extension processing directly into the transport
network.
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+-----------+ +-----------+ +-------+
+service.org+ +service.org+ +foo.com|
+----+------+ +-------+---+ +----+--+
| | |
+-----------+ +----+-+ +----+-----------+--+
+service.org+---+DC Net| | DC Net |
+-----------+ +---+--+ +-------------+-----+
| |
+-+--+ +-+--+
+-----+SAR4| |SAR5|
| +-+--+ +-+--+
+------+ +-+--+ +----+ |
+Client+--------+SAR1+-------------+ +SAR6+ |
+------+ +----+ | +-+--+ |
| | |
+------+ +----+ ++-----+----+ |
+Client+--------+SAR2+------------+IPv6 Net(s)+---------+
+------+ +----+ +---+--+----+ (----)
| | ( )
+------------------+ +----+ | | +----+ ( Other )
+MyMobile.org/video+--------+SAR3+----+ +----+SAG1+----( Domains )
+------------------+ +----+ +----+ ( )
(------)
SAR: Service Address Router
SAG: Service Address Gateway
Figure 1: ROSA System Overview
ROSA endpoints start with discovering their ingress Service Address
Router (SAR), e.g., through DHCP extensions or through utilizing the
Session Management Function (SMF) in 5G networks [TS23501]. An
endpoint may discover several ingress SARs for different categories
of services, each SAR being part of, e.g., a category-specific ROSA
overlay, which in turn may be governed by different routing policies
and differ in deployment (size and capacity). The category discovery
mechanism may be subject to specific deployments of ROSA and thus is
likely outside the scope of this document at this point.
Services are realized by service instances, possibly at different
network locations. Those instances expose their availability to
serve requests through announcing the service address of their
service to their ingress SAR, which in turn distributes suitable ROSA
routing state across the SARs in its domain. The lacking tie of
service addresses to the network topology, and thus the lacking
possibility to aggregate relationships of service addresses to
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routing locators, poses a scalability challenge (specifically to
address Req 2.a in Section 3.4) However, the routing tables in ROSA
are bounded by the number of services explicitly announcing their
service to ingress SARs, while utilizing explicit interconnection
(see Section 3.6) to other ROSA domains or the Internet for any
service requested in the domain that has not previously been
announced.
To invoke a service, a ROSA client sends an initial request,
addressed to a service, to its ingress SAR, which in turn steers the
request (possibly via other SARs) to one of possibly many service
instances. See Section 3.4 for the required SAR-local forwarding
operations and end-to-end message exchange and Section 3.3 for the
needed changes to ROSA clients. Conversely, non-ROSA services may
continue to be invoked using existing means for service routing, such
as DNS, GSLB, Alto and others.
We refer to initial requests as 'service requests'. If an overall
service transaction creates ephemeral state, the client may send
additional requests to the service instance chosen in the (preceding)
service request; we refer to those as 'affinity requests'. With
this, routing service requests (over the ROSA network) can be
positioned as on-path service discovery (winth in-band data),
contrasted against explicit, often off-path solutions such as the
DNS.
In order to support transactions across different service instances,
e.g., within a single DC, a sessionID may be used, as suggested in
[SOI2020]. Unlike [SOI2020], discovery does not include mapping
abstract service classes onto specific service addresses, avoiding
semantic knowledge to exist in the ROSA shim layer for doing so.
With the above, we can outline the following design principles that
guide the development for the solutions described next:
* Service addresses have unique meaning only in the overlay network.
* Service instance IP addresses have meaning only in the underlay
networks, over which the ROSA domain operates.
* SARs map service addresses to the IP addresses for the next hop to
send the service request to, finally directed to the service
instance IP address.
* Within the underlay network, service instance IP addresses have
both locator and identifier semantics.
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* A service address within a ROSA domain carries both identifier and
locator semantics to other nodes within that domain but also other
ROSA domains (through the interconnection methods shown in
Section 3.6).
* Affinity requests directly utilize the underlay networks, based on
the relationships build during the service request handling phase.
We can recognize similarities of these principles with those outlined
for the Locator Identifier Separation Protocol (LISP) in [RFC9299]
albeit extended with using direct IP communication for longer service
transactions.
3.2. Examples of Possible Message Types
Apart from affinity requests, which utilize standard IPv6 packet
exchange between the client and the service instance selected through
the initial service request, ROSA introduces three new message types.
Here, we present example encodings, shown in Figure 2.
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Header | Hdr Ext Len | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| Instance=IP |
| Service=ID |
| Constraint=txt |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Service Announcement
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Header | Hdr Ext Len | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| Client=IP |
| Ingress=IP |
| Service=ID |
| Port=port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Service Request
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Header | Hdr Ext Len | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| Client=IP |
| Ingress=IP |
| Service=ID |
| Port=port |
| Instance=IP |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Service Response
Figure 2: ROSA message types
Given the overlay nature of ROSA, clients, SARs, and service
instances are destinations in the IPv6 underlay of the network
domains that the overlay spans across. This is unlike approaches
such as [I-D.huang-service-aware-network-framework], which place the
service address into the destination address of the respective IPv6
header field, although [I-D.ma-intarea-encapsulation-of-san-header]
also foresees the encapsulation into the IPv6 EH, as suggested here.
Istead, we propose to use the destination option EH [RFC8200], where
Figure 2 shows the options carried, proposed here as using a TLV
format for the extension header with Concise Binary Object
Representation (CBOR) [RFC8949] being studied as an alternative. The
EH entries shown are populated at the client and service instance,
while read at traversing SARs.
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A service address is encoded through a hierarchical naming scheme,
e.g., using [RFC8609]. Here, service addresses consist of
components, mapping existing naming hierarchies in the Internet onto
those over which to forward packets, illustrated in the forwarding
information base (FIB) of Figure 3 as illustrative URLs. With
components treated as binary objects, the hierarchical structure
allows for prefix-based grouping of addresses, reducing routing table
size, while the explicit structure allows for efficient hash-based
lookup during forwarding operations, unlike IP addresses which
require either log(n) radix tree search software or expensive TCAM
hardware solutions.
Note that other encoding approaches could be used, such as hashing
the service name at the ROSA endpoint or assigning a service address
through a mapping system, such as the DNS, but this would require
either additional methods, e.g., for hash conflict management or
name-address mapping management, which lead to more complexity.
With the service announcement message, a service instance signals
towards its ingress SAR its ability to serve requests for a specific
service address. Section 3.5 outlines the use of this message in
routing or scheduling-based traffic steering methods.
The service request message is originally sent by a client to its
ingress SAR, which in turn uses the service address provided in the
extension header to forward the request, while the selected service
instance provides its own IP locator as an extension header entry in
the service response. In addition to the service address, suitable
port information is being provided (through upper layer protocols),
allowing to associate future affinity requests with their initial
service requests.
The next section describes the SAR-local forwarding operations and
the end-to-end message exchange that uses the extension header
information for traversing the ROSA network, while Section 3.6
outlines the handling of service addresses that have not been
previously announced within the client-local ROSA domain.
3.3. Changes to Clients to Support ROSA
Within endpoints, the ROSA functionality is realized as a shim layer
atop IPv6 and below transport protocols. For this, endpoints need
the following adjustments to support ROSA:
* Adapting network layer interface: Introducing service addresses
requires changes for discovering the ingress SAR and issuing
service requests as well as maintaining affinity to a particular
service instance. This could be achieved by providing a new
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address type (e.g., ADDR_SA) at the socket interface, linking the
service address to the returned handle, while utilizing socket
options to assign constraints to receiving sockets, utilized in
the announcement of the service address. New sockets may be
provided, at least for initial rollouts, though user space
libraries, while alternatively, a UDP-based, encapsulation of
traffic to the ingress SAR could be used.
* Transport protocol integration: Our design aligns with existing
transport protocols, like TCP or QUIC, albeit with changes
required to utilize the new service address type. Typical
handshakes, particularly for transport security, align well with
the initial service request message exchange, before affinity
requests would send the actual (now possibly encrypted) payload.
* Changes to application protocols: The most notable change for
application protocols, like HTTP, would be to bypass the DNS for
resolving service names, using instead the aforementioned
different (service) socket type. These adaptions are, however,
entirely internal to the protocol implementation. Given the ROSA
deployment alongside existing IP protocols, those changes to
clients can happen gradually or driven through (e.g., edge SW)
platforms.
3.4. SAR Forwarding Engine
The SAR operations are typical for an EH-based IPv6 forwarding node:
an incoming service request or response is delivered to the SAR
forwarding engine, parsing the EH for relevant information for the
forwarding decision, followed by a lookup on previously announced
service addresses, and ending with the forwarding action.
Figure 3 shows a schematic overview of the forwarding engine with the
forwarding information base (FIB) and the next hop information base
(NHIB) as main data structures. The NHIB is managed through a
routing protocol, see Section 3.5, with entries leading to announced
services.
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incoming service request/response
-------------------------------------|| Next Hop
\/ Information Base
Forwarding Information Base +----------+ +-+--------+----+
+------------------+--------+ |EH parsing| |#|Next Hop|Cost|
|Service address |Next Hop| +----||----+ |#| IP |Cost|
+------------------+--------+ \/ +-+--------+----+
| service.org | 4, 5, 0| +----------+ |0| SAR5 | 2 |
+------------------+--------+ | SAR | +-+--------+----+
| foo.com | 1 |-->|Forwarding| |1| SAR6 | 1 |
+------------------+--------+ | Decision | +-+--------+----+
|MyMobile.org/video| 2 | +----||----+ |2| SAR2 | 4 |
+------------------+--------+ \/ +-+--------+----+
| * | 3 | +----------+ |3| SAR1 | 2 |
+------------------+--------+ | SA/DA | +-+--------+----+
|Adjustment|<--|4| SI1 | - |
+----||----+ +-+--------+----+
\/ |5| SI2 | - |
+----------+ +-+--------+----+
|IP packet |
|forwarding| Outgoing service
| engine | request/response
+----------+------------------->
Figure 3: SAR forwarding engine model
The FIB is dynamically populated by service announcements via the
intyer-SAR routing protocol, with the FIB including only one (ROSA
next hop) entry into the NHIB when using routing-based methods (rows
0 to 3 in Figure 3), described in Section 3.5.2. Scheduling-based
solutions (see Section 3.5.1), however, may yield several dynamically
created entries into the NHIB (items 0, 4 and 5 in Figure 3, where
SI1 and SI2 represent the IPv6 address announced by the respective
service instances) as well as additional information needed for the
scheduling decision; those dynamic NHIB entries directly identify
service instances locations (or their egress as in item 0) and only
exist at ingress SARs towards ROSA clients.
We expect the number of forwarding entries to be limited by the
explicit relations service providers may have with their ROSA
provider. In other words, we do not expect the FIB to include ALL
possible service names but those explicitly announcing their service
(and being authorized by the ROSA provider doing so). In our use
cases of [I-D.mendes-rtgwg-rosa-use-cases], those services may be
very limited in numbers, particularly if we foresee dedicated ROSA
providers to aim at realizing those use cases.
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For a service request, a hash-based service address lookup (using the
Service EH entry) is performed, leading to next hop (NH) information
for the IPv6 destination address to forward to (the final destination
address at the last hop SAR will be the instance serving the service
request).
Forwarding the response utilizes the Client and Ingress EH fields,
where the latter is used by the service instance's ingress SAR to
forward the response to the client ingress SAR, while the former is
used to eventually deliver the response to the client by the client's
ingress SAR, ensuring proper firewall traversal of the response back
to the client. We have shown in prototype realizations of ROSA that
the operations in Figure 3 can be performed using eBPF [eBPF]
extensions to Linux SW routers, while [SarNet2021] showed the
possibility a realizing a similar design using P4-based platforms.
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Client Ingress Service Service
SAR Instance Instance
(CIP) (SAR IP) (SI1 IP) (SI2 IP)
---------------------------------------------------------------------
ServiceRequest
(ClientIP,SAR IP)
(CIP, SAR IP, ServiceID)
--------------------->
\ Determine ROSA
/ and, ultimately, IP Next Hop
ServiceRequest
(SAR IP, SI1 IP)
(CIP, SAR IP, ServiceID)
--------------------->
\ Generate
/ Response
ServiceResponse
(SI1 IP, SAR IP)
(CIP, SAR IP, ServiceID, SI1 IP)
<---------------------
ServiceResponse
(SAR IP, CIP)
(CIP, SAR IP, ServiceID, SI1 IP)
<---------------------
AffinityRequest
(CIP, SI1 IP)
------------------------------------------->
\ Generate
/ Response
<-------------------------------------------
Figure 4: ROSA message exchanges
Figure 4 shows the resulting end-to-end message exchange, using the
aforementioned SAR-local forwarding decisions. We here show the IP
source and destination addresses in the first brackets and the
extension header information in the second bracket.
We can recognize two key aspects. First, the SA/DA re-writing
happens at the SARs, using the EH-provided information on service
address, initial ingress SAR and client IP locators, as described
above. Second, the selection of the service instance is signalled
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back to the client through the additional Instance EH field, which is
used for sending subsequent (affinity) requests via the IPv6 network.
As noted in the figure, when using transport layer security, the
service request and response will relate to the security handshake,
thereby being rather small in size, while the likely larger HTTP
transaction is sent in affinity requests. As discussed in Section 8,
0-RTT handshakes may result in transactions being performed in
service request/response exchanges only.
3.5. Traffic Steering
Traffic steering in ROSA is applied to service requests for selecting
the service instance that may serve the request, while affinity
requests use existing IPv6 routing and any policies constraining
traffic steering in this part of the overall system. At receiving
service endpoints, service provisioning platforms may use additional
methods to schedule incoming service requests to suitable resources
with the ingress point to the service provisioning platform being the
service endpoint for ROSA.
In the following, we outline two approaches for traffic steering.
The first uses ingress-based scheduling decisions to steer traffic to
one of the possible service instances for a given service address.
The second follows a routing-based model, determining a single
destination for a given service address using a routing protocol,
similar to what is suggested in
[I-D.huang-service-aware-network-framework].
We envision that some services may be steered through scheduling
methods, while others use routing approaches. The indication which
one to apply may be derived from the number of next hop entries for a
service address. In Figure 3, service.org uses a scheduling method
(with instances connected to SAR5 being exposed as a single instance
to ROSA, using DC-internal methods for scheduling incoming requests),
while the other services are routed via SARs.
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We furthermore envision an interface to exist between the ROSA
provider and the underlying network provider, exchanging routing
policy relation information. The richness of this interface depends
on the specific business relation between both providers, i.e., the
ROSA and the network provider. In integrated settings, where ROSA
and network provider may belong to the same commercial entity, this
interface may provide rich routing policy relation information, such
as network latency and bandwidth information, which in turn may be
used in the ROSA traffic steering decisions. In other, more
disintegrated deployments, the information may entirely be limited to
SLA-level information with no specific runtime information exchanged
between both providers. The exact nature of this interface remains
for further study.
Important here is that traffic steering is limited to a single ROSA
domain, i.e., traffic steering is not provided across instances of
the same service in different ROSA domains; traffic will always be
steered to (ROSA) domain-local instances only.
3.5.1. Ingress Request Scheduling
Traffic steering through explicit request scheduling follows an
approach similar to application- or transport-level solutions, such
as GSLB [GSLB], DNS over HTTPS [RFC8484], HTTP indirection [RFC7231]
or QUIC-LB [I-D.ietf-quic-load-balancers]: Traffic is routed to an
indirection point which directs the traffic towards one of several
possible destinations.
In ROSA, this indirection point is the client's ingress SAR.
However, unlike application or transport methods, scheduling is
realized in-band when forwarding service requests in the ingress SAR,
i.e., the original request is forwarded directly (not returned with
indirection information upon which the client will act), while
adhering to the affinity of a transaction by routing subsequent
requests in a transaction using the instance's IP address.
Scheduling commences to a possibly different instance with the start
of a new transaction.
For this, the ingress SAR's NHIB needs to hold information to ALL
announced service instances for a service address. Furthermore, any
required information, e.g., capabilities or metric information, that
is used for the scheduling decision is signalled via the service
announcement, with (frequent) updates to existing announcements
possible. Announcements for services following a scheduling- rather
than a routing-based steering approach carry suitably encoded
information in the Constraint field of the announcement's EH, leading
to announcements forwarded to client-facing ingress SARs without NHIB
entries stored in intermediary SARs.
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In addition, a scheduling decision needs to be realized in the SAR
forwarding decision step of Figure 3. This may require additional
information to be maintained, such as instance-specific state,
further increasing the additional NHIB data to be maintained.
Examples for scheduling decisions are:
* Random selection of one of the service instances for a given
service address, not requiring any additional state information
per service address. Announcing the service instance is required
once.
* Round robin, i.e., cycling through service instance choices with
every incoming service request, requiring to keep an internal
counter for the current position in the NHIB for the service
address. Announcing the service instance is only required once.
* Capability-based round robin: Cycle through service instances in
weighted round robin fashion with the weight (as additional
information in each NHIB entry) representing a capability, e.g.,
number of (normalized) compute resources committed to a service
instance. Announcing the service instance requires an update when
capabilities change (e.g., during re-orchestration). Weights
could be expressed as numerals, limiting the needed semantic
exposure of service provider knowledge and thereby supporting the
possible separation of service and communication network provider.
The solution in [CArDS2022] realises a compute-aware selection
through such decision.
* Metric-based selection: Select service instance with lowest or
highest reported metric, such as load, requiring to keep
additional metric information per service instance entry in the
NHIB. Frequent signalling of the metric is required to keep this
information updated.
Although each method yields specific performance benefits, e.g.,
reduced latency or smooth load distribution, [OnOff2022] outlines
simulation-based insights into benefits for realising the compute-
aware solution of [CArDS2022] in ROSA.
3.5.2. Routing Across Multiple SARs
In order to send a service request to the `best' service instance
(among all announced ones) using a routing-based approach, we build
NHIB routing entries by disseminating a service instance's
announcement for a given service address S, arriving at its ingress
SAR. This distribution may be realized via a routing protocol or a
central routing controller or a hybrid solution.
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If no particular constraint is given in the announcement's EH
Constraint field, shortest path will be realized as a default policy
for selecting the `best' instance, routing any client's request to S
the nearest service instance available.
Alternatively, selecting a service instance may use service-specific
policies (encoded in the Constraint field of the EH, with the
specific encoding details being left for future work). Here,
multiple constraints may be used, with [Multi2020] providing a
framework to determine optimal paths for such cases, while also
conventional traffic engineering methods may be used.
Through utilizing the work in [Multi2020], a number of multi-criteria
examples can be modelled through a dominant path model, relying on a
partial order only, as long as isotonicity is observed. Typical
examples here are widest-shortest path or shortest-widest routing
(see [Multi2020]), which allow for performance metrics such as
capacity, load, rate of requests, and others. However, metrics such
as failure rate or request completion time cannot directly be
captured and need formulation as a max metric. Furthermore, metrics
may not be isotonic, with Section 3.4 of [Multi2020] supporting those
cases through computing a set of dominant attributes according to the
largest reduction. [Multi2020] furthermore shows that non-restarting
or restarting vectoring protocols may be used to compute dominant
paths and to distribute the routing state throughout the network.
However, the framework in [Multi2020] is limited to unicast vectoring
protocols, while the routing problem in ROSA requires selecting the
'best' path to the 'best' instance, i.e., as an anycast routing
problem. To capture this, [Multi2020] could be extended through
introducing a (anycast) virtual node, placed at the end of a logical
path that extends from each service instance to the virtual node.
Selecting the best path (over the announced attributes of each
service instance) to the virtual node will now select the best
service instance (over which to reach the virtual node in the
logically extended topology).
Alternatively, ROSA routing may rely on methods for anycast routing,
but formulated for service instead of anycast addresses. For
instance, AnyOpt [AnyOpt2021] uses a measurement-based approach to
predict the best (in terms of latency) anycast (i.e. service)
instance for a particular client. Alternatively, approaches using
regular expressions may be extended towards spanning a set of
destinations rather than a single one. Realizations in a routing
controller would likely improve on convergence time compared to a
distributed vector protocol; an aspect for further work to explore.
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3.6. Interconnection
There are two cases for interconnection: access to (i) non-ROSA
services in the public Internet and (ii) ROSA services not domain-
locally announced but existing in other domains.
For both cases, we utilize a reserved wildcard service address '*'
that points to a default route for any service address that is not
being advertised in the local domain. This default route is the
service address gateway (see Figure 1), ultimately receiving the
service request to the locally unknown service.
Upon arriving at the SAG, it searches its local routing table for any
information. If none is found, it consults the DNS to retrieve an IP
address where the service is hosted; those mappings could be cached
for improving future requests or being pre-populated for popular
services.
For case (i), the resolution returns a server's IP address to which
the SAG sends the service request with its own IP address as source
address. The service response is routed back via the SAG, which in
turn uses the Ingress EH information to return the response to the
client via its ingress SAR.
For case (ii), the IP address would be that of the SAG of the ROSA
domain in which the service is hosted. For this, a domain-local
service instance would have exposed its service, e.g., Mobile.com/
video Figure 1, by registering its domain-local SAG IP address with
the mapping service. To suitably forward the request, the SAG adds
its own IP address as the value to an additional SAG label into the
extension header. At the destination SAG, the service address
information, extracted from the extension header, is used to forward
the service request based on ROSA mechanisms. For the service
response, the destination SAG uses the SAG entry in the EH to return
the response to the originating ROSA domain's SAG, which in turn uses
the Ingress information of the EH to return the response via the
ingress to the client.
Given the EH deployment issues pointed out in [SHIM2014], a UDP-based
encapsulation may overcome the observed issues, not relying on the EH
being properly observed during the traversal over the public
Internet. Furthermore, while Figure 1 shows the SAG as an
independent component, we foresee deployments in existing PoPs. This
would allow combining provisioning through frontloaded PoP-based
services and ROSA services. Any service not explicitly announced in
the ROSA system would lead to being routed to the PoP-based SAG,
which may use any locally deployed services before forwarding the
request to the public Internet.
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4. Extensions to Base ROSA Capabilities
ROSA, as defined in Section 3, can be extended to address various
capabilities useful for specific or across a number of use cases.
The following provides a list of those possible extended
capabilities. At this stage, we would expect those capabilities to
be defined in more detail in separate drafts, complementing the ROSA
'base' specification, as defined in this current draft.
4.1. Supporting Different Namespace Encodings
Although most of our examples assume the use of URL-based service
addresses, encoded using [RFC8609], supporting other, e.g., corporate
service, namespaces may be desired. [RFC8609] generally supports
this and could thus be used.
As briefly alluded to in Section 3.2, other encodings to that
following [RFC8609] may be used, focussing on different ways to
represent a service address differently, including linking it to the
service name used at the application level.
One such encoding may be that of a unique service address per service
name, with the linkage between both provided through the DNS. Here,
the client sends an initial DNS query with the URL of the purported
service or application. Instead of requesting a resolution to a
locator, however, is the request for mapping between the URL and the
service address of ROSA, where the service address has been assigned
as part of the domain name registration (which may be done after
initial registration of the domain name for backward compatibility).
Service addresses here may be simply encoded as numerals, where
uniqueness is achieved through linking to the domain name
registration and thus DNS mapping. Encoding in the respective EH
header field (see Section 3.2) would be shorter and thus more
efficient, still achieving the desired uniqueness in the SAR
forwarding process to avoid ambiguity in forwarding decisions. The
drawback is the need for the additional DNS mapping step (albeit only
required once per application, where the service address could be
stored persistently for later use), while also the additional DNS
mapping will need standardization (likely in the form of a new DNS
record).
Another possible encoding, without the aforementioned explicit DNS
mapping step, could be to explicitly hash the service name into a
service address at the ROSA endpoint, operating on those hash values
for service announcement and requests. Due to the large service
namespace, hash conflicts may, however, occur, which needs resolving
at the SAR (which may operate on a service address for a service
request for a different, but same hashed, service address of an
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announcement service). Further study is needed into the probability
for such hash conflicts and possible mitigation methods for such
conflicts.
If the use of different encoding methods beyond [RFC8609] was to be
considered, appropriate modifications to the EH fields need to be
done to signal the used encoding method for the service address.
4.2. Supporting Multi-Homing of Service Instances
Multi-homed service instances may benefit from path-aware routing
decisions after mapping service addresses to service instance
addresses. To that end, service instances would need to advertise
multiple instance IPs as part of their service announcement.
The optimal path may differ while a client communicates with a
service instance; this is in particular likely for mobile clients.
This provides some complication for affinity requests; in such a
case, the service instance IP is no longer sufficient to identify a
service instance, merely to locate a particular path.
Multi-homing issues in connection with aircrafts also extend to
Unmanned Aircraft Systems (UAS). Rather than focusing on passenger
experience, multi-homing over commercial off-the-shelf (COTS)
communications modules such as 5G or IEEE 802.11 provides command,
control and communications (C3) capabilities to Unmanned Aerial
Vehicles (UAV; drones). Despite the difference in focus, the
technical challenges in maintaining connection quality are largely
equivalent.
Multi-homing thus either requires an undesirable further resolution
step from a service instance identifier to a (optimal path) locator.
Alternatively, ROSA message types may be extended to include a
distinct service instance identifier and service instance locator
identifiers, i.e., IP addresses, which provides sufficient
information for SARs to map to specific and changing locators, while
retaining the affinity to the service instance by identifier.
4.3. Supporting 0-RTT TLS
TBD Dirk
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4.4. Supporting Transaction Mobility
When it comes to the transaction mobility in which the serving
service instance needs to be shifted to another selected alternative
instance, the ROSA service address could provide a good starting as
an location-independent ID. Other than TCP for which the client and
server have to maintain strict machine state, UDP-based protocol
could be extended with the service address to be treated as the
connection ID rather than the traditional 4-tuple including the host
destination address when the server does not have to maintain session
state. The chief gain here is the service connection could remain
intact when the serving service instance has been switched over at
ROSA level (routing plane).
As part of the ability to switch over from one service instance, ROSA
may explicitly support that mobility in that the choice of the (new)
service instance is explicitly made within the service-specific
traffic steering method. For this, ROSA may introduce a separate
message alongside the service request message (see see Section 3.2),
which not only allows for the ingress SAR to perform the same routing
policy as if it was sent through a new service request message, but
may also include application-specific context data to facilitate the
needed application state transfer from the original service instance
to the new one. Here, the in-band capability of a ROSA request is
being used to carry this context data as part of the new ROSA
message.
4.5. Supporting Service Function Chaining
Service Function Chaining (SFC) [RFC7665] allows for chaining the
execution of services at L2 or L3 level, targeting scenarios such as
carrier-grade NAT and others. The work in [RFC8677] extends the
chaining onto the name level, using service names to identify the
individual services of the chain, even allowing combinations of name
and L2/L3-based chains.
Although [RFC8677] is tied into a realization of the SFF (service
function forwarder) using a path-based forwarding approach, the
concept of name-based SFCs can equally be realized utilizing ROSA.
4.6. Supporting Privacy-Compliant Communication
The exposure of service-related information in the ROSA EHs may be
seen as a privacy issue, particularly when utilizing the service name
as the basis for the service address formulation. Although Section 8
outlines the possible use of service categories (instead of finer-
grained service names) as input into the service address formulation,
it is also desirable to protect the privacy of fine-grained service
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address information, should the specific ROSA deployment make use of
them.
Beyond using encryption methods to protect the ROSA EH information,
such privacy methods could also include the obfuscation of client and
transit information as well, thus moving into the space of routing
privacy, as outlined for instance in
[I-D.ip-address-privacy-considerations]
5. Prototype-based Insights
To come before IETF118 with description of planned demo to
demonstrate some of the benefits for using ROSA.
6. Open Issues
There are a number of open issues with the following list providing a
non-exhaustive list of examples:
1 A ROSA control plane is required for handling aspects of ingress
SAR discovery and signalling of service instance announcements to
the ROSA network, either to ingress SARs only (for services
utilizing traffic scheduling mode) or across all domain-internal
SARs. Here, the signalling for achieving interconnections, based
on the methods outlined in Section 3.6, is also required to be
specified.
2 Prototypical but also possibly simulation-based insights into
benefits are desirable to motivate the adoption of ROSA.
7. Conclusions
This draft outlined an architecture for service-specific traffic
steering as an alternative to existing service-based routing methods
that use explicit resolution steps. Instead, the architecture
presented in this document advocates an approach of in-band
signalling of service addresses, possibly carried across IPv6 EH-
based shim overlay, followed by the IPv6-based transfer of subsequent
packets in similarity to existing SBR methods. The architecture
suggests to employ routing and ingress scheduling based methods to
provide the desired dynamicity of anycast decisions that are outlined
as desirable for the use cases in [I-D.mendes-rtgwg-rosa-use-cases].
As next steps, we plan on extending various aspects of the ROSA
operations, e.g., describing control plane aspects such as SAR
discovery as well as a possible routing protocol. We expect that
some of those aspects, such as for a ROSA control plane, are captured
in separate works.
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We furthermore have plans on bringing an eBPF-based prototypical
realization of the forwarding behaviour in Section 3.4 to future IETF
events, e.g., for a hackathon participation to showcase ROSA-based
applications in a test setup.
8. Security Considerations
Aligned with security considerations in existing service provisioning
systems, we address aspects related to authenticity, i.e., preventing
fake service announcements, confidentiality, both in securing
relationship as well as payload information, and operational
integrity.
* Announcement security: A key exchange between service and network
provider may be used to secure the service announcement for
ensuring an authorized announcement of services. Self-certifying
identifiers could be used for this purpose
* Relationship security: Using service addresses at the routing
layer poses not just a privacy but possibly also a net neutrality
problem, allowing for non-ROSA elements to discriminate against
specific service addresses. Similar to
[I-D.per-app-networking-considerations], service addresses could
reflect service categories, not services themselves. Service
endpoints to those category-level services can use information in
the secured payload (e.g., the URL in an HTTP-based service
invocation) to direct the traffic accordingly. The downside of
such model is a possible convergence towards a PoP-like model of
service provisioning, since exposing an entire service category
naturally requires provisioning many possible services under that
category, likely favouring large-scale providers over smaller
ones; an imbalance that ROSA intends to change, not favour. Work
on identity privacy in ILNP [ILNP2021] has shown that ephemeral
identifiers may increase the private nature of the communication
relation; a direction that needs further exploration in the
context of our work. Also, the service address in the extension
header could be encrypted, based on a key exchange during the SAR
discovery. However, the impact of such mechanism would need
further study.
* Transport-level security: Given the often sensitive nature of
service requests, payload security is key. We adopt techniques
used in TLSV1.3 [RFC8446], providing a 1-RTT handshake for
communication between formerly untrusted parties. While the
initial 'Client Hello' is sent as a service request, the
subsequent communication uses the topological address of the
responding server in an affinity request. Using pre-shared keys
may allow for communication between trusted client and service
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instances, e.g., where the client is provided by the service
authority and preconfigured with a pre-shared key. This results
in a 0-RTT handshake with the 'Client Hello' including the initial
service data, encrypted with the pre-shared key. This comes with
known forward-secrecy issues and should be avoided in networks
with untrusted intermediary nodes. Alternatively, the service's
public key could encrypt the initial security handshake, akin to
the solutions proposed for Encrypted Client Hello (ECH), using the
DNS for obtaining the public key.
* Bandwidth DoS: We assume network provider level mechanisms to
restrict traffic injected both by the service provider and client,
including for the number of service advertisements in order to
control the routing traffic.
* Denying routing service: A SAR could maliciously deny forwarding
of client requests, which is no different from denying IP packet
forwarding. In both cases, we assume an existing commercial
relationship that avoids such situation.
9. Privacy Considerations
The exposure of service-related information in the ROSA EHs may be
seen as a privacy issue, particularly when utilizing the service name
as the basis for the service address formulation. As discussed in
Section 4.6, extensions to the base ROSA capabilities may address
this issue to ensure the privacy of the clients' communication
relations in ROSA deployments, where needed.
10. IANA Considerations
This draft does not request any IANA action.
11. Acknowledgements
Many thanks go to Ben Schwartz, Luigi Iannone, Mohamed Boucadair,
Tommy Pauly, Joel Halpern, Daniel Huang, and Russ White for their
comments to the text to clarify several aspects of the motiviation
for and technical details of ROSA.
12. Informative References
[AnyOpt2021]
Zhang, Z., April, T., Chandrasekaran, B., Choffnes, D.,
Maggs, B. M., Shen, H., Sitaraman, R. K., Yang, X., Zhang,
X., and T. Sen, "AnyOpt: predicting and optimizing IP
Anycast performance", Paper ACM SIGCOMM, 2021.
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[CArDS2022]
Khandaker, K., Trossen, D., Khalili, R., Despotovic, Z.,
Hecker, A., and G. Carle, "CArDS:Dealing a New Hand in
Reducing Service Request Completion Times", Paper IFIP
Networking, 2022.
[eBPF] "What is eBPF?", Technical Report eBPF Foundation, 2022,
<https://ebpf.io/what-is-ebpf/>.
[GSLB] "What is GSLB?", Technical Report Efficient IP, 2022,
<https://www.efficientip.com/what-is-gslb/>.
[I-D.eip-arch]
Salsano, S., ElBakoury, H., and D. Lopez, "Extensible In-
band Processing (EIP) Architecture and Framework", Work in
Progress, Internet-Draft, draft-eip-arch-02, 19 June 2023,
<https://datatracker.ietf.org/doc/html/draft-eip-arch-02>.
[I-D.huang-service-aware-network-framework]
Huang, D., Tan, B., and D. Yang, "Service Aware Network
Framework", Work in Progress, Internet-Draft, draft-huang-
service-aware-network-framework-01, 22 November 2022,
<https://datatracker.ietf.org/doc/html/draft-huang-
service-aware-network-framework-01>.
[I-D.ietf-quic-load-balancers]
Duke, M., Banks, N., and C. Huitema, "QUIC-LB: Generating
Routable QUIC Connection IDs", Work in Progress, Internet-
Draft, draft-ietf-quic-load-balancers-16, 21 April 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-quic-
load-balancers-16>.
[I-D.ip-address-privacy-considerations]
Finkel, M., Lassey, B., Iannone, L., and B. Chen, "IP
Address Privacy Considerations", Work in Progress,
Internet-Draft, draft-ip-address-privacy-considerations-
03, 10 January 2022,
<https://datatracker.ietf.org/doc/html/draft-ip-address-
privacy-considerations-03>.
[I-D.ma-intarea-encapsulation-of-san-header]
Ma, L., Zhao, D., Zhou, F., and D. Yang, "Encapsulation of
SAN Header", Work in Progress, Internet-Draft, draft-ma-
intarea-encapsulation-of-san-header-00, 23 October 2022,
<https://datatracker.ietf.org/doc/html/draft-ma-intarea-
encapsulation-of-san-header-00>.
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[I-D.mendes-rtgwg-rosa-use-cases]
Mendes, P., Finkhäuser, J., Contreras, L. M., and D.
Trossen, "Use Cases and Problem Statement for Routing on
Service Addresses", Work in Progress, Internet-Draft,
draft-mendes-rtgwg-rosa-use-cases-00, 26 June 2023,
<https://datatracker.ietf.org/doc/html/draft-mendes-rtgwg-
rosa-use-cases-00>.
[I-D.per-app-networking-considerations]
Colitti, L. and T. Pauly, "Per-Application Networking
Considerations", Work in Progress, Internet-Draft, draft-
per-app-networking-considerations-00, 15 November 2020,
<https://datatracker.ietf.org/doc/html/draft-per-app-
networking-considerations-00>.
[ILNP2021] Yanagida, R., Bhatti, S., and G. Haywood, "End-to-end
privacy for identity and location with IP", Paper 2nd
Workshop on New Internetworking Protocols, Architecture
and Algorithms, 29th IEEE International Conference on
Network Protocols, 2021.
[Multi2020]
Ferreira, M. A. and J. L. Sobrinho, "Routing on Multi
Optimality Criteria", Paper ACM SIGCOMM, 2020.
[OnOff2022]
Khandaker, K., Trossen, D., Yang, J., Despotovic, Z., and
G. Carle, "On-path vs Off-path Traffic Steering, That Is
The Question", Paper ACM SIGCOMM workshop on Future of
Internet Routing and Addressing (FIRA), 2022.
[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
DOI 10.17487/RFC7231, June 2014,
<https://www.rfc-editor.org/info/rfc7231>.
[RFC7665] Halpern, J., Ed. and C. Pignataro, Ed., "Service Function
Chaining (SFC) Architecture", RFC 7665,
DOI 10.17487/RFC7665, October 2015,
<https://www.rfc-editor.org/info/rfc7665>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>.
Trossen, et al. Expires 10 January 2024 [Page 29]
Internet-Draft ROSA July 2023
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[RFC8484] Hoffman, P. and P. McManus, "DNS Queries over HTTPS
(DoH)", RFC 8484, DOI 10.17487/RFC8484, October 2018,
<https://www.rfc-editor.org/info/rfc8484>.
[RFC8609] Mosko, M., Solis, I., and C. Wood, "Content-Centric
Networking (CCNx) Messages in TLV Format", RFC 8609,
DOI 10.17487/RFC8609, July 2019,
<https://www.rfc-editor.org/info/rfc8609>.
[RFC8677] Trossen, D., Purkayastha, D., and A. Rahman, "Name-Based
Service Function Forwarder (nSFF) Component within a
Service Function Chaining (SFC) Framework", RFC 8677,
DOI 10.17487/RFC8677, November 2019,
<https://www.rfc-editor.org/info/rfc8677>.
[RFC8949] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", STD 94, RFC 8949,
DOI 10.17487/RFC8949, December 2020,
<https://www.rfc-editor.org/info/rfc8949>.
[RFC9299] Cabellos, A. and D. Saucez, Ed., "An Architectural
Introduction to the Locator/ID Separation Protocol
(LISP)", RFC 9299, DOI 10.17487/RFC9299, October 2022,
<https://www.rfc-editor.org/info/rfc9299>.
[SarNet2021]
Glebke, R., Trossen, D., Kunze, I., Lou, Z., Rueth, J.,
Stoffers, M., and K. Wehrle, "Service-based Forwarding via
Programmable Dataplanes", Paper 1st Intl Workshop on
Semantic Addressing and Routing for Future Networks, 2021.
[SHIM2014] Naderi, H. and B. Carpenter, "Putting SHIM6 into
practice", Paper 2014 Australasian Telecommunication
Networks and Applications Conference (ATNAC), 2014.
[SOI2020] Jiang, S., Li, G., and B. Carpenter, "A New Approach to a
Service Oriented Internet Protocol", Paper IEEE INFOCOM
2020 - IEEE Conference on Computer Communications
Workshops (INFOCOM WKSHPS), 2020.
Trossen, et al. Expires 10 January 2024 [Page 30]
Internet-Draft ROSA July 2023
[TS23501] "System architecture for the 5G System (5GS); Stage 2
(Release 16)", Technical Report 3GPP TS 23.501 V16.11.0
(2021-12), 2021,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=3144>.
Authors' Addresses
Dirk Trossen
Huawei Technologies
80992 Munich
Germany
Email: dirk.trossen@huawei.com
URI: https://www.dirk-trossen.de
Luis M. Contreras
Telefonica
Ronda de la Comunicacion, s/n
Sur-3 building, 1st floor
28050 Madrid
Spain
Email: luismiguel.contrerasmurillo@telefonica.com
URI: http://lmcontreras.com/
Jens Finkhaeuser
Interpeer gUG
86926 Greifenberg
Germany
Email: ietf@interpeer.io
URI: https://interpeer.io/
Paulo Mendes
Airbus
82024 Taufkirchen
Germany
Email: paulo.mendes@airbus.com
URI: http://www.airbus.com
Trossen, et al. Expires 10 January 2024 [Page 31]
